It's difficult to perceive on first glance. In Toronto, the air is clean, crime rates are low and healthcare is universal. Yet an undercurrent of anxiety courses through the country's public discourse and its media; it dominates conversations in coffee shops and university hallways. A volley of recent polarising political developments has led many Canadians to ask whether their country's reputation as a tolerant, environmentally conscious international peacemaker is suddenly in doubt.

Some, though not all, of this tendency has been blamed on the country's conservative leadership, which gained a parliamentary majority in May last year. The prime minister, Stephen Harper, has tightened immigration policy, struck a hard line in the Middle East and adjusted environmental policy to encourage controversial oil extraction programmes in the country's vast northern hinterlands.

"Everybody knew that Harper would have a different agenda from that of the Liberals," said Herb Grubel, a professor emeritus at Simon Fraser University and former member of parliament. "What he has been doing is putting into effect some of these ideas."

Immigration

Canada is one of the few countries in the world that still looks to immigration as a tool for nation-building – 20% of Canadians were born abroad, and new immigrants add 0.8% to the country's population each year. Multiculturalism has been a formal policy since 1971; it's taught in the country's elementary schools.Yet over the past year immigration authorities have radically adjusted the criteria for successful applications and cut resettlement programmes en masse. In June, Ottawa provoked a firestorm of controversy – and sparked a spate of doctors' protests – when it eliminated all but the most basic healthcare for certain refugee groups. Last week, immigration minister Jason Kenney announced that 3,100 people would have their Canadian citizenship revoked for hiring immigration consultants to falsify their documents. Eleven thousand aspiring citizens are still under investigation."There's a lot that we need to fix pronto, otherwise the message goes out to the world that we're not a welcoming place," said Ratna Omidvar, president of Toronto-based immigration foundation Maytree.

Some analysts say the changes point to a deep-rooted, yet widely ignored undercurrent of racism in Canadian society. In late August, news leaked that the Bank of Canada had removed an east Asian-looking woman from preliminary designs of its new $100 bill, replacing her with a caucasian. Chinese groups were outraged, causing the bank to issue a public apology.

"Fighting racism in the States is like punching a brick wall, but fighting it in Canada is like punching a marshmallow – it always melds back to the same shape," said Minelle Mahtani, a professor at University of Toronto Scarborough. "We live in an ostrich-head-in-the-sand-like denial that racism exists in this country, and yet systemic discrimination is the norm."

Quebec

Intolerance is also rife in francophone Quebec, which elected the separatist Parti Quebecois leader Pauline Marois as premier on 4 September. Marois's ascent to power has been shadowed by violence: a man shot two people at the Montreal convention centre where her party was celebrating its victory, killing one and leaving the other in a critical condition. "The English are waking up!" the man shouted in French during his arrest, eliciting widespread soul-searching about the depth of the province's linguistic divide.

Quebec was already reeling from a spring full of huge student-led street demonstrations. The movement, often referred to as the "maple spring", began as a smattering of peaceful protests against tuition fee hikes. But when the then incumbent Liberal administration passed an emergency law to crack down on demonstrators, simmering discontent exploded into full-blown dissent. At the height of the movement, almost 1,000 protesters were arrested in a 400,000-strong Montreal march, some of them as young as 15.

Analysts say that Marois is unlikely to hold a referendum on independence – she is fighting from a minority position and popular support for secession has waned since Quebec's last referendum in 1995.

Yet she has invited controversy by proposing measures that would restrict freedom of language and religion in the province. Her promise to strengthen Quebec's French language charter would restrict access for some groups to English junior colleges. Her "secularism policy" would ban religious symbols such as headscarves, skullcaps and hijabs in public offices. Yet it would allow crucifixes, which, according to Marois, symbolise traditional Quebec culture.

"There is still a large group of ethnic nationalists who believe that Quebec should be for the pure-wool francophones who founded this province," said Bruce Hicks, a professor of political science at Concordia University in Montreal. "Pauline Marois, out of deference to this more extremist group in her party, sort of pandered to that."

Tar sands

Almost 4,000km away from Montreal, the vast plains of northern Alberta province lie at the heart of another national debate. The region contains 140,000 sq km of "tar sands" – a mixture of sand, water and clay the texture of cold molasses – which contain copious amounts of highly viscous petroleum. Over the past decade, technological developments and soaring oil prices have made its extraction economically viable, making it a prime destination for major international oil companies.

Critics say that Harper's environmental policy favours these companies over the long-term wellbeing of Canada's natural environment. Last month, Ottawa cancelled almost 3,000 environmental reviews on proposed development projects across the country, many of which involved tar sands oil extraction.

The Canadian government has approved a 730-mile pipeline from the Alberta tar sands to the shores of British Columbia, where it will be loaded on to oil tankers and shipped to Asian markets. Environmental groups have launched a united stand against the project, claiming that Enbridge – the Calgary-based company at its head – has been dishonest about the risk of potential oil spills. In 2010, an Enbridge pipe burst in northern Michigan, leaving a still-visible oily sheen on the area's rivers.

"Canada has always been a natural resource extraction country – it's logging, it's hydro-power, it's mining, it's oil and gas," said Susan Casey-Lefkowitz, international director at the Natural Resources and Defence Council. "But the tar sands is such a big resource, and it drew such major players, that it's really reshaped the way the government has dealt with environmental issues."

First Nations

Tar sands oil extraction has also underscored an already fraught relationship between the federal government and Canada's nearly 700,000 indigenous people, called First Nations. For decades, resource extraction on First Nations land and chronically underfunded schools have left many of these communities mired in poverty, alcoholism and disease.

Gerald Amos, former chief of the Haisla Nation in coastal British Columbia, said that while his community used to survive by catching oolichan fish – a type of smelt – in the nearby Kitamaat river, this traditional way of life is long gone. Toxic dumping has destroyed the river, driving the fish to the brink of extinction. Amos fears that the Enbridge project will consume what's left of the wilderness near his home, where the pipeline will meet the coast.

"I think that the big issue for a lot of communities – one that really hasn't been grappled with yet – is the cumulative impact of what we call progress," he said. "And that's something that I think communities are going to have to start grappling with very quickly."